TOKYO, July 16 (Reuters) - Toyota Motor Corp is likely to seek damages from Nippon Steel & Sumitomo Metal Corp , the automaker said, after smoke released in June from the steelmaker's Nagoya plant left soot and tar stains on Toyota vehicles parked at shipping yards.

Japan's biggest automaker said on Wednesday soot and tar stuck to around 23,000 vehicles that were parked at two yards in Aichi prefecture, central Japan, after a power failure at the Nippon Steel Nagoya plant on June 22 led to the release of smoke from coke ovens.

Around 20,000 of the vehicles were for export to various countries excluding North America, while the rest were due for sale in Japan, Toyota spokeswoman Kayo Doi said. Overseas vehicle shipments are expected to be delayed by a week to a month and domestic shipments by around three weeks, she said.

Toyota employees are working to clean the surface of the vehicles, a process which takes about an hour per car, Doi said. She declined to provide details on which car models were affected, on the financial cost of shipment delays and cleaning efforts, nor on the amount of compensation Toyota might seek from Nippon Steel.

The steelmaker also declined to give details on the incident. "We will respond in a sincere manner," spokesman Masato Suzuki said. (Reporting by Yoko Kubota; Editing by Kenneth Maxwell)